Decompression sickness (DCS) is an extremely variable disease with multiple possible symptoms, many of which are non-specific. There are no laboratory tests or other investigations that confirm the diagnosis, and diving physicians frequently have to integrate knowledge of diving, diver behaviour, DCS pathophysiology, DCS presentation and other competing diagnoses in formulating an appropriate response to reports of symptoms after diving. Not surprisingly, there are frequent diagnostic conundrums. This often occurs in the context of situations where the implications of the diagnosis are profound, such as when the victim is aboard a charter boat in a remote location and evacuation will cause a major disruption to multiple high-paying customers. These situations can be very challenging for the diving physician.
This chapter outlines the known patterns of presentation and manifestations of DCS based largely around effects by organ system. Before proceeding to that discussion, however, the discussion attempts to clarify some confusing issues in relation to terminology and classification of the dysbaric diseases.